Multi-dimensional column chromatography

As chromatography is the most efficient separation method which can be applied to these samples, it has been shown that the on-line coupling of such columns can successfully apply to water analysis [ 35 ]. This method is derived from the multi-dimensional gas chromatography (MDGC) technique. Double oven instruments were recently developed which are specifically dedicated to this type of MDGC analysis [36]. 

Mengelers, M.J.B. Polman, A.M.M. Aerts, M.M.L. Kuiper, H-A. Van Miert, A.S.J.PA.M. Determination of sulfadimethoxine, sulfamethoxazole, trimethoprim and their main metabolites in lung and edible tissues from pigs by multi-dimensional liquid chromatography. J.Liq.Chromatogr., 1993,16, 257-278 [muscle kidney liver LOD 10-50 ng/g column temp 30 coliunn-switching]... 

Column selector valves can be added on as accessories to allow column switching for multi-dimensional chromatography (to increase the resolution of very complex samples such as in proteomics) or for automatic column selection (up to six columns) to facilitate methods development using different columns. 

Jia et al. (2005) developed a two-dimensional (2-D) separation system of coupling chromatography to electrophoresis for profiling Escherichia coli metabolites. Capillary EC with a monolithic silica-octadecyl silica column (500 x 0.2 mm ID) was used as the first dimension, from which the effluent fractions were further analyzed by CE acting as the second dimension. Multi-dimensional separations have found wide applications in biomedical and pharmaceutical analysis. 

The idea of chromatographic CF is the use of timely chromatographic apparatus and technique for this purpose. Basically, it is the application towards copolymer investigation of what is known among chromatographers as multi-dimensional or coupled column chromatography. 

Proteomics, the study of the entire set of proteins encoded by a genome, is an area of active research conducted by many research organizations.32-38 As mentioned in Chapter 4, proteomics samples are too complex to be sufficiently resolved by a single HPLC column with a typical peak capacity of 200-400. Flowever, multi-dimensional chromatography with two orthogonal columns can potentially extend peak capacity by -15,000. The traditional approach is to use IEC (strong cationic, SCX) to fractionate the complex sample, followed by RPC-MS/MS to characterize each fraction, as shown in the example in Figure 7.31. 

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